1. Field of the Invention
The invention relates to a power-generating station for the generation of electric power from gas produced from coal by means of a combination process in which the waste heat of the gas turbine is utilized for a following steam process and coal gas from a coal gasification plant is used as fuel.
2. Description of the Prior Art
In one known plant of this type, the exhaust gas line of the gas turbine block is connected on the primary side to a steam generator which is part of a steam turbine block which also contains a high pressure and a low pressure turbine, a condenser, a feedwater tank and a feedwater pump (DE-Z"Brennstoffe-Waerme-Kraft", 1979, pages 214 ff). A special relationship of the coal gasification plant and the gas-turbine block consisting of an air compressor, combustion chamber, gas turbine and generator may consist that a steam generator for utilizing the raw gas heat is followed by a heat exchanger for heating the purified gas by the raw gas and that the steam generator arranged ahead of the raw-gas/purified gas heat exchanger is designed as a high pressure steam generator, the output of which on the secondary side is connected to the output of the steam generator of the steam turbine block (British Pat. No. 20 75 124; U.S. Journal "Applied Energy", 1982, page 91).
In another known combined process, a coal gasification plant and a gas turbine block are related to each other such that, in addition to the purified gas from the coal gasification plant, part of the nitrogen produced in the air separation plant is fed to the combustion chamber and the excess part is admixed, entering the gas turbine air compressor, to the air stream drawn from the atmosphere, for the purpose of reducing the nitrous oxides (German DE-OS No. 31 00 751).